Answer Key to Class: 7 ENGLISH 1. (A) Correct Spelling  lightning  essential (B) Meanings  fame /  tie , attach /  old , ancient /  flourish / (C) Opposites:  arrest , capture  innocent , honest Parts of Speech:  application / applicant apply applicable  measurement measure measuring/ measureable 2. Articles and Prepositions A small boy came running so fast that he felt as if the earth were spinning. He entered the room through a window and hid himself behind the door. 3. (A) Complete Sentences  I shall act upon your advice.  He doesn't do anything when it is call for prayer.  Can you speak different languages? (B)  A lot of money is spent by her.  Did she take tea in the evening?  The maid has swept the backyard. 4. Sentences  recently  establish  grateful 5. Translation  Did you complete your work on time?  My father regularly goes for a morning walk.  They will be preparing for the examination. SCIENCE 1. Options for Blanks (i) chromosomes (ii) Sublimation (iii) sound / light (iv) Concave 2. Short Answers (i) Photosynthesis: The process by which plants make their own food using carbon dioxide and water in the presence of sunlight and chlorophyll is called photosynthesis. Equation : carbon dioxide + water sunlight Glucose + Oxygen chlorophyll Importance : All the living things use both of the products of photosynthesis in respiration to produce energy. (ii) Difference METALS NON-METALS Most metals are found in solid state. Non-metals are found in solid, liquid and gaseous state. Most metals are hard solids. Most non-metals are not hard. Metals have high melting and boiling points. Low melting and boiling points. Good conductors of electricity. Bad conductors of electricity (except graphite) (iii) Labelling and Function 1. Endoplasmic reticulum 2. Nucleus 4. Cell Wall Function: Supports the cell and gives shape 3. Vacuole Function: Stores waste materials, water, air and food particles 5. Mitochondrion (iv) 6. Chloroplast Sound is a form of energy. Large amount of energy can produce louder sounds. If a drummer beats the drum with a lot of force it will make a loud sound. We can conclude that More energy= Loud sound Less energy = Soft sound MATHEMATICS 1. Options for Blanks (i) 0 (ii) 0 ÷ 2. = ÷ + = ÷ + = ÷ + = ÷ + = ÷ = ÷ = × × − multiplicative identity itself or 1 − − × × × × × = =1 Purchase price of 4 bananas = Rs 10 Purchase price of 1 banana= Rs Purchase price of 80 bananas= Rs × 80 = Rs 200 Sale price of 5 bananas = Rs 8 Sale price of 1 banana = Rs Sale price of 80 bananas= Rs × 80 = Rs 128 As sale price < purchase price Loss = P.P – S.P = Rs.200 – Rs.128 = Rs.72 Loss% = ×100% = 3(y-4)–4(2y+3) = 3(y+1)+1 3y–12–8y–12=3y+3+1 –5y–24 = 3y+4 –5y–3y= 4+24 –8y=28 y= 28/–8 = –7/2 × × . loss × × . 3. (iv) × × = 3. + (iii) × 100% % = 36% 5. As, Product of two numbers = LCM ×HCF 3328 = LCM × 16 = LCM 208 = LCM So, LCM of two numbers = 208 208 16 3328 32 128 128 0